Air conditioning apparatus



April 11, 1939. LEA 2,153,932

AIR coummonmq APPARATUS A Filed Aug. 27, 1936 2 Sheets-Sheet 1 c, Q N 4 INVENTOR Edward 15' Lea $91471, JMWC 1 4 I 71:17

ATTORNEYS .April 11, 1939. E. s. LEA

AIR CONDITIONING APPARATUS Fil ed Aug. 27, 1936 2 Sheets-Sheet 2 INVENTOR .E'dwarddfiea 64 /v%7iv ATTORNEYS Patented Apr. 11, 1939 UNITED STATES PATENT OFFICE AIR CONDITIONING APPARATUS Application August 27, 1936, Serial No. 98,113

1 Claim.

My present invention, considered from one aspect, is concerned with improvements in air conditioning methods and apparatus and particularly with improvements in apparatus of the general 5 character disclosed in my copending application Serial No. 37,847, filed August 26, 1935.

Considered from another aspect the invention may have a wide and varied range of usefulness in connection with the control of refrigerating apparatus regardless of the purpose for which such apparatus may be used.

In my earlier application above identified I disclose a compact air conditioning machine through which the air to be conditioned is drawn. The

16 air is subjected first to the action of a coarse washing spray and then passed through a mist filled region to humidify it and then subjected to a swirling action to centrifugally eliminate excess moisture. I also disclose a cooling coil in the 20 tank from which the spray water is drawn, re-

frigerant from this coil being passed through a heat exchanger coil arranged beyond the mist filled region and near the outlet of the machine. This second bell was intended to serve the twofold purpose of additionally cooling the air leaving the machine and super-heating the refrigerant before it passed back to the compressor, thereby avoiding frosting of the pipe leading back to the compressor.

My present invention is concerned with the provision of a control mechanism for obtaining the most eflicient results from the general type of machine above described, although the principles involved have a wider field of usefulness.

In accordance with the present invention I preferably place a thermostatic valve in the refrigerant line itself where it is not exposed to variations in air temperature. Preferably also I place this control valve (which regulates the admission of refrigerant through the expansion valve into the water cooling coil) at such a position in the heat exchanger near the outlet of the machine that part of the heat exchanger cooling unit acts primarily to additionally cool the air passing through it and part of the heat exchanger acts to superheat the refrigerant passing back to the compressor so that only thoroughly dry refrigerant is returned to the compressor.

Cooling coils in air conditioning machines have heretofore proven generally objectionable unless they were either constantly sprayed with water or immersed in a swirling bath of water particularly in cases where these coils were provided 5 with fins which would sweat and upon which dirt and dust might collect. In the present case the heat exchanger which is provided near the outlet of the machine preferably includes a series of finned pipes. Since however the only air which passes over it has been thoroughly washed before 6 reaching the heat exchanger, it contains no dust or dirt which might deposit thereon.

Preferably the heat exchanger consists of three headers, an inlet header into which gas from the spray water cooling coil flows, an intermediate 10 header which receives the gas after it has served to additionally cool the air leaving the outlet of the machine and a third header receiving substantially dry gas through a series of pipes from the intermediate header and from which the dry 15 gas is withdrawn and returned to the compressor.

My improved control valve which may itself be of standard construction, and is enclosed in a gas and water tight casing, is located in the intermediate header and is directly responsive to 20 the temperature of the refrigerant in such header, this valve regulating in convenional fashion the admission of refrigerant through an expansion valve into the spray water cooling coil.

' Thus one portion of the heat exchanger serves primarily as an additional cooling means for the air leaving the machine, and the other portion or section thereof serves primarily as a super-heater for warming up and drying out the refrigerant 30 gas before it leaves the last header for return to the compressor. No wet raw refrigerant gas goes back to the compressor.

I am cognizant of the fact that it is not broadly new to install a thermostatic valve directly in 35 the refrigerant line' where it is responsive only to refrigerant temperatures rather than outside temperatures but I believe that my special method of installation and the particular arrangement of coils and control valve may take 40 a wide range of usefulness in connection with various refrigerating problems other than the cooling and dehumidification of air.

The control valve here employed is extremely simple and inexpensive. The heat exchanger in 45 which the valve is mounted is designed for economy of construction and efliciency of operation. The application of the valve to the unit in such a manner that the .valve is completely protected against direct heat exchange with either air or 50 I fully apparent from the following description in l connection with the accompanying drawings wherein,

Fig. 1 is a diagrammatic vertical sectional view through an air conditioning machine embodying the invention.

Fig. 2 is an enlarged side elevational view of the heat exchanger and the control valve which it carries.

Fig. 3 is a plan view of this heat exchanger with part of the intermediate header broken away to show the valve mounting, and,

Fig. 4 is a diagrammatic view of the compressor, the spray water cooling coil showing the connections between the control valve and the expansion valve.

Insofar as the air conditioning machine illustrated herein is concerned, various features of it have been disclosed and claimed in my prior applications notably applications Serial No. 755,916 filed December 4, 1934, now Patent No. 2,079,574 dated May 4, 1937, and Serial No. 37,847, filed August 26, 1935, and while I have shown the present invention as applied to this general type of machine it is to be understood that it may be applied with equal effectiveness to air conditioning units of various other constructions wherein a refrigerated water spray is used to cool and/or wash and/or dehumidify air passing through the unit.

As above noted however, it is particularly advantageous to employ this invention where a heat exchanger in the form of a combined air cooling and refrigerant superheating unit is placed in such a position that only thoroughly washed air traverses its surface.

The general type of air conditioning apparatus illustrated in Fig. 1 embodies my improved control mechanism and my improved heat exchanger unit, the rest of the construction being substantially similar to that illustrated in my prior application Serial No. 755,916 now Patent No.

The machine includes a casing indicated generally at In which has an open bottom extending into a tank ll adapted to receive water to be used for washing and dehumidifying the air passing through the machine. Supported upon the top of the casing l and resting on a cushioning ring I2 is a motor base plate l3. This base plate supports an electric motor l4 which drives a. shaft I 5 extending downwardly into the cas- The upper portion of the casing provides a volute conduit I6 more fully described in my copending application just referred to and at the center of this volute conduit, shaft l5 carries a sirocco fan ll. Below the fan the shaft mounts a slinger unit indicated generally at l8. This .unit includes a slinger 19 for delivering a small spray into the fan H where it is broken up into a fine mist by the fan, and a lower slinger 20 for throwing a violent washing spray radially into the space between the bottom of the volute passageway l6 and the surface of the water in the tank.

Both slingers draw water from a well 2| arranged in the bottom of the tank and into which water flows through a valve 22 thermostatically controlled inany suitable manner as by the push rod 23 operated on by the thermostatically controlled cam 24.

Air enters the machine through the top of an inlet passageway 25, passing through a filter 26 and being drawn through and around a screen 21. Screen 21 like the inner screen 28 serves to break up the spray from the lower slinger 20, the air which is drawn inwardly by the fan I! being subjected to the action of the spray and then being violently discharged from the fan I! through the volute conduit [6.

In passing through the inner portion of the conduit the air is thoroughly humidified by the mist in the region of the fan and as it leaves the conduit it passes upwardly through an outlet passageway 29 in which is located my improved air cooling and refrigerant super-heating heat exchanger unit designated generally at 30.

A float 3| may control an inlet valve through which water is admitted to the tank. Suspended in any suitable manner from the casing is a coil type evaporator 32, certain coils of which are disposed above the liquid level in the tank and certain coils of which are submerged in the liquid. From the outlet of this evaporator coil refrigerant is conducted through a pipe line 33 to the inlet header 34 of the unit 30 the structural details of which will be more fully hereinafter described.

In the diagrammatic view of Fig. 4, 35 indicates the thermostatic expansion valve through which refrigerant is admitted to the evaporator 32. 36 represents the compressor which forces refrigerant through the line 31 to the expansion valve 35. 38 represents the outlet header of the unit 30 from which dry refrigerant gas passes through pipe 39 to the compressor 36 and 40 represents the intermediate header of the unit 30 within which is mounted the temperature responsive means indicated generally at 4|, and having a bulb 41 which is of the fluid pressure operated type. The pressure within the bulb 41 is controlled by the temperature of the refrigerant in the header 40 and this pressure is communicated directly through a conduit 42 to the operating element of the expansion valve 35.

Since the expansion valve and control therefor are entirely conventional no details thereof have been shown.

For economy of space the header 34 is arranged directly above header 38, these headers being horizontally disposed. A downwardly inclining series of parallel finned tubes 43 connect header 34 with the header 40, this header being horizontally disposed at a level intermediate the levels of the headers 34 and 38. A second series of finned parallel tubes 44 lead from the header 40 down to the header 38, these tubes lying under tubes 43.

At one end of the header 40 the latter is in open communication with a sleeve 45 projecting axially of the header and preferably extending beyond the casing lll of the refrigerating machine. Welded onto this sleeve 45 is one element 46 of a coupling piece which holds the bulb 41 in place. Only the outer cylindrical shell of this bulb has been shown but this shell is secured by the coupling piece 46 and the complementary coupling piece 48 in such a position that the major portion of this shell projects inwardly into the header 4!]. The tube end 49 which projects from this bulb is merely used for filling the tube 42 and the necessary parts of the thermostatic valve device with the desired gas, tube end 49 being then closed and sealed.

In order to fully appreciate the manner in which the bulb 41 and its associated air cooling and refrigerant super-heating unit 30 functions, it is necessary to describe somewhat more fully the operation of the conditioner unit illustrated in Fig. 1.

amaeaa In normal operation of the machine the air entering through the inlet 25 is thoroughly washed by the cold water from the spray projected by the slinger 20. The air is also substantially cooled by this spray since the spray water is refrigerated by the coil 32. The air is drawn upwardly into the sirocco fan I! and projected with a violent swirling motion through the volute l6 and as it leaves the machine it comes into heat exchanger relationship with the heat exchanger unit 30. At the region of the fan thorough humidiflcation is effected by the finely divided mist produced by the delivery of water from the slinger l9 against the fan blades.

If the flow of refrigerant through the expansion valve 35 into the coil 32 is regulated by the temperature of the spray water or regulated by the temperature of the air in any part of the machine, there is no assurance that there will not be either gas blocking in the lower coil 32 or the delivery of raw gas back to the compressor from the heat exchanger. Not only is it necessary to place the thermostatic control valve in some position where it is controlled by the actual temperature of the refrigerant but the particular location of thisvalve in the refrigerant circuit is of great importance. directly to air temperatures the cessation of operation of the machine and the consequent quick rise of the air temperature would result inthe expansion valve being opened or closed at too frequent intervals. The same thing would be true if the valve was Were the valves subjected directly responsive to spray water temperature. However, when the refrigerant itself is the medium which directly controls the thermostat, 'much more eiiicientcontrol of the refrigerating system is had. Furthermore, the positioning of this valve at the critical point which insures against improper refrigeration by the spray water coil as well as against the return of raw gas to the compressor contributes greatly to the efliciency of the system.

Various changes and alterations may be made in the general form and arrangement of the parts described without departing from the spirit or scope of the appended claim.

I claim:

In an air conditioning device of the character in which air to'be conditioned is subjected to a refrigerated water spray, a cooling system including a heat exchanger for cooling the spray water, a second heat exchanger in series with said first heat exchanger and arranged to receive refrigerant therefrom, said second heat exchanger having an evaporator portion and a superheater portion and means directly responsive to the temperature of the refrigerant. flowing from said evaporator portion for controlling the flow of refrigerant to said first heat exchanger, and means for circulating the spray cooled air first in heat exchange relation with said superheater portion and then in heat exchange relation with said evaporator portion, whereby to superheat the refrigerant flowing from said second heat exchanger and to additionally cool the air.

EDWARD S. LEA. 

